Effects of pirenzepine and atropine on basal lower esophageal pressure and gastric acid secretion in man: a placebo-controlled randomized study.

Pirenzepine is a tricyclic antimuscarine drug with antisecretory effect on gastric secretion and inhibitory effect on esophageal peristalsis (EP). The effect of pirenzepine in graded doses on basal and pentagastrin-stimulated lower esophageal sphincter pressure (LESP) was studied in 8 volunteers. The effect was compared with the effect of atropine and placebo using a double dummy technique. Intravenously administered pirenzepine and atropine inhibited basal LESP and EP regardless of the employed doses. No difference between atropine and pirenzepine could be demonstrated. The pentagastrin-stimulated LESP was inhibited in patients treated with pirenzepine perorally (50 mg b.i.d.). Basic acid output was significantly reduced by pirenzepine or atropine in contrast to peak acid output. We conclude that muscarinic receptors of type M play a role in the LES function in man.